Answer:
c. (12.12, 18.48)
Step-by-step explanation:
Hello!
The study variable is X: number of times a racehorse is raced during its career.
The average number is X[bar]= 15.3 and the standard deviation is S= 6.8 obtained from a sample of n=20 horses.
To estimate the population mean you need that the variable has a normal distribution, in this case, we have no information about its distribution so I'll assume that it has a normal distribution. With n=20 the most accurate statistic to use for the estimation is a Students-t for one sample, the formula for the interval is:
X[bar] ± 

[15.3 ± 2.093 *
]
[12.12; 18.48]
Using a significance level of 95% you'd expect that the true average of times racehorses are raced during their career is included in the interval [12.12; 18.48].
I hope it helps!
<h3>
Answer: £66</h3>
Your teacher may want you to leave off the pounds sign.
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Explanation:
x = amount Bill gets
3x = amount Sam gets, because he gets three times as much
x+3x = 4x = total amount of money
4x = 88
x = 88/4
x = 22
Bill gets £22
3x = 3*22 = 66
Sam gets £66
Note that 22+66 = 88 to help confirm the answer.
Answer:
DeShawn pays .67 cent per pound of sugar
So if x people were surveyed,

people owned a bike and

did not.
The difference between them is 72:

x-\frac{1}{8} [/tex] =72
so this means that

x=72
let's simplify:

x=72
and divide by 3:

x=24
and mupliply by 4:
x=96
so 96 people were surveyed